Not firing on all cylinders

UK forum for general and technical discussion about the Z3 roadster

Moderator: Gazza

Post Reply
Rodent
Joined: Mon 22 May, 2017 08:34
Posts: 29

  Z3 roadster 2.2i

Not firing on all cylinders

Post by Rodent » Wed 24 Apr, 2019 21:13

My 2.2 straight 6 zed has started intermittently running rough. I can start up and drive for a while, but then will start to sound like it's only running on a few cylinders. Then later it will recover and run fine. And typically mot is due next week!
I have Inpa and kind of know how to use it. When I read the fault codes there was nothing obvious. It did have faults including:
DME - F1 DME: Misfire cylinder 4 - combustion Miss with cylinder cutout (p1349 or p0304)
This fault was shown for cylinders 4, 5 and 6.
Does anyone know if this points to any particular faulty component. I'm wondering if I should replace the plugs, then the coils and see if that helps.
The car is 2001. It's done 128k miles but only about 15k by me. I've not changed the plugs or coils since I owned it and I don't have any service history for it.
Thanks

mrscalex
Joined: Fri 13 Mar, 2015 09:14
Posts: 888

  Z3 roadster 1.9

Re: Not firing on all cylinders

Post by mrscalex » Wed 24 Apr, 2019 21:57

Pull the DME out and make sure the cylinder firing pin-outs aren't corroded and preventing the signal from getting to the coil.

I had this issue and if I remember correctly it was cylinder 4 - significant as it is in the most prone position to water ingress.

I would say the chances are low it will be this but it's probably the easiest thing to check.

I should advise if it is this error it can lead to engine damage if fuel is getting into the cylinder and not being ignited.
ImageImage
2001 Z3 2.2 Topaz Blue (Trudy) - Keeper rebuilt from a write-off
2002 Z3 2.2 Titan Silver (Cookies) - Keeper rebuilt having been bought with a seized engine
2002 Z3 3.0 Sapphire Black (Peanut) - Keeper awaiting rebuilding having been bought as an abandoned project
Plus Willy, Kodak & Maycee - All 2.2 Sport projects. Yes, 6 is a lot of Z3s :)
Always happy to try and help with spares :)

Rodent
Joined: Mon 22 May, 2017 08:34
Posts: 29

  Z3 roadster 2.2i

Re: Not firing on all cylinders

Post by Rodent » Thu 25 Apr, 2019 09:59

Thanks mrscalex, i’ll have a look at the DME today

woodsta888
Joined: Wed 25 May, 2011 10:26
Posts: 29

  Z3 roadster 2.0
Location: Exmouth

Re: Not firing on all cylinders

Post by woodsta888 » Thu 25 Apr, 2019 16:35

I'd disconnect the MAF to see if that changes anything and it's not faulty.

Mice was running rough as, loads of missing and would then be OK. Stop engine and restart and missing again.

My local indy replaced mine then the issue came straight back so it wasnt that. What it was in the end is the solenoid that controls the fuel tank gases into the charcoal filter. This stopped working intermittently. May also be called EVAP canister purge control valve. fortunately these are a common BMW part and £10 for 2nd hand one off ebay. Remove it and hook it up to 12v supply and it should click on and off. Mine didnt.

When you open the fuel cap after it runs rough do you get a big rush of air?

There is also a small pipe that goes into the charcoal reservoir that may have perished also so check that.

This is what it look like and where it is on the engine block albeit on E46

Howard Adams
Joined: Mon 10 Oct, 2016 16:39
Posts: 57

  Z3 roadster 3.0i

Re: Not firing on all cylinders

Post by Howard Adams » Fri 26 Apr, 2019 17:36

Misfire, start with the basics, replace the spark plugs, see which one is black? If misfiring replace the coil pack. Most misfires are ignition related.
Good luck.
H

User avatar
Gazza
Site Admin
Joined: Tue 04 Oct, 2005 21:58
Posts: 9414

  M roadster S54
Location: Romford Essex

Re: Not firing on all cylinders

Post by Gazza » Fri 26 Apr, 2019 19:48

I’d try the coil pack test first.

https://youtu.be/JLDo7Jk78ac
Gazza

"Understeer is when you hit the wall with the front of the car, oversteer is when you hit the wall with the rear of the car. Horsepower is how fast you hit the wall and torque is how far you take the wall with you"

Z3 S54 M roadster Image, BMW Z1, BMW M3 CSL, Z4M Coupe
ImageImage

Rodent
Joined: Mon 22 May, 2017 08:34
Posts: 29

  Z3 roadster 2.2i

Re: Not firing on all cylinders

Post by Rodent » Sat 27 Apr, 2019 10:45

Ok, I did the coil test and there wasn't much change between each one, they all made a slight change when each coil was disconnected in turn.
Coil 4 looked a bit white (overheated??). I took the no 4 coil and plug out and it got worse......lots of oil around the plug insulated bit, the tip was dry and normal coloured. Also the plug was already loose when I put the spark plug socket on it!
Took number 5 out and it was much the same as number 4, maybe even slightly more oil, and it was not tightly in either.
Took all the rest out and they were all dry and looked ok.
Also, on start up, there is a regular ticking comes from the 4 and 5 top of engine area. The car idles ok, but if I take the oil filler cap off, it struggles to the point of almost stalling.
Is this bad news?

Rodent
Joined: Mon 22 May, 2017 08:34
Posts: 29

  Z3 roadster 2.2i

Re: Not firing on all cylinders

Post by Rodent » Sat 27 Apr, 2019 13:16

Update...... took the valve cover off. The gaskets around the plug holes were hard and brittle. Looks like a new gasket is needed. Looks like around £40 for genuine or half of that for a pattern part

Post Reply

Who is online

Users browsing this forum: Bing [Bot] and 2 guests